I installed the I-dot pros with the green ring last week. Been to the range twice. So far I like them a lot. I have a lot of trouble with stock sights unless I black out the rear.
I argued with myself a lot before buying these. Couldn't decide on green or orange. Noticed yesterday that my local dealer has a barely used gen 4 21 for a great price. If I can make that happen I may put the orange on it.